US2563162A - Method of making self-binding nuts - Google Patents

Description

Filed Nov.

FIG.3

25 FIG.4

D. c. ECKENBECK ET AL METHOD OFMAKING SELF-BINDING NUTS 3 Sheets-Sheet 1 2 4 QYWMM 20 Dami- EcKenbecK incl Philip slau htev Gamma;

g- 7, 1951 D. c. ECKENBECK ET AL 2,563,162

METHOD OF MAKING SELF-BINDING NUTS Filed Nov. 25, 1945 :s sheets-sheet 2 FIG. 6

26 20\ s V a x swam M Dana C. Eekenbeck and Philip E. Slaughter g- 7, 1951 D. c. ECKENBECK ET AL 2,563,162

METHOD OF MAKING SELF-BINDING NUTS Filed Nov. 23, 1945 Sheets-Sheet 5 3 m D n [c/(enbeck and Philip E. Slaughter Patented Aug. 7, 1951 ED STATES PATENT oFFlcE Dana o. Eckenbeck and Philip nrslaugmer, Minneapolis,-,Minn.

Application- November 23, 1945, Serial No. 630,234 I 1 This invention relatesto attaching or securing elements and relates more particularly "to self binding nuts and method of making the same. A general object of this invention is to provide a dependable and effective self binding nut and a simple, economicaland commercially'practicalmethod formaking'the same.

Another object of thisinvention isto provide a novel self binding nut with highly efiici'en't means for maintaining sustained torque between the "load taking surfacesor the threads of the nut body and bol-t-toresist unthreading.-

The prior art has longknown' the lock nut in which various types of--detents are used to prevent retrograde movementofthe nut. Such devices are efiicient for a limitedtime only for their repeated re-use either damages the thread structure of'the bolt or the detents'become so dulled as to be worthless for their intended purpose.

Other expedients have been advanced from time to-time, one of which is gripping fingers extending from the "nut with an inward radial bend part way across at the top of the nut bore so that they are forced. apart by the entrant action of a .bolt stem. The: fingers generally grip the bolt at or near the top only andthe fingers soon lose their grip and/or damage $116.:bolt threads prohibiting re-use of the bolt or the nut,

or .both. V y

The present inventionis designedto overcome the objectionable characteristics of the prior art and at the same time to produce a nut which when threaded over a bolt stem .or the like, eiiectively grips the bolt fora considerable distance without biting thereinto, and with a radial and axial tension supplemented by an annular torque so that the nut binds itself against retrogression of eitherthe nut'or the bolt stem. Still another object of the invention is to provide a self binding nut of the character above stated which may be repeatedly used over and over without appreciable loss of efficiency and without substantially'anyfdamage to the threaded structure of either the nut or the stud. I

The various objects and features of our invention will be understood from the following detailed description ofa. preferred form of the self binding nut and means for carrying out the method of the invention, butit is to be understood that the details may be varied within the scope of the inventionas claimed. I The invention will be describedwith reference to the accompanyi drawing, in which like ref erence numeralsidenote like parts and inwhichg 2-Claims.- (CI. 86)

Figure l is .a. top plan: view of a nut made in accordance with the invention, prior to distortion of thegr'ipping members,

Figure 2 is an elevation partly in section :of the nut;

Figure 3 is an elevation in section illustrating the nut entering the'forming tool on the short axis of such tool; I

Figure 4 is an elevation: in section showing the nut completely in the fbr'ming tool on the short axis;

Figure 5 is an elevation in section showing the entering of theform-ing' tool on the wide axis in full lines and completely in the forming tool on the wide axis in dotted lines;

Figure 6 is an elevation-partly in sectionuof the completed nut showing the shape ofth holding members on the'short axis;

Figure 7 is an elevation'partly in section of the completed nut showing the shape of the holding members on the wide axis;

Figure 8 is an axial section through a nut and bolt associated in service;

Figure 9 is a top plan view with'parts broken away of the shape of the nut when completely in the forming tool;

Figure 10 isa'top plan view with parts broken away of the nut afterbeing deformed.

Anut made in 'accordancewith this invention comprises, a body 20, which may have a hexagonal shape, having an axial bore extending therethrough from its top to its bottom. The top face is provided with gripping members 21.

One suitable way'offorming the holding mem hers is by providing a reduced axial extension on the top of the nutand then slotting the extension at a plurality of points as shown-in Figure 1. The slots 22 extend from the outer end of the extension to the topface portion of the nut but preferablymot into the nut.

In producing the nut, the blank with its integral extensions is bored, threaded, and slotted, or slotted and threaded for the entire axial extent'of theresuIting boreas shown in Figure 2. This pro'videsthe holding members with arcuateinner' faces 23 threaded in continuation of'the nut bore threads? and" at the" same helix angle, the curvature of'tnef inner surface 230i thelholding members being sub'-' stantially in the radius of the nut bore.

.After the initial formation of the nut as shown inFigures '1 and '2, the"holdinglmeinbers"are distorted as shown in Figures 6. and 7'. This" is accomplished bybending the holding" me'nriber'sto the form of substantially an ellipse at their In the operation of deforming the nut holding members,

the punch is forced down axially over the nut holding members, as indicated in Figures 3, 4, and 5, and whereupon the members 2| will given their peculiar deformation. I

Nuts constructed in accordance with this invention when applied over and threaded home on bolt stems and the like, are effectively thread locked thereon with a, firm self binding action under sustained torque ofthe holding members for substantially the full length of the holding members. I v

Figures 6 and 7 show that the members 21 are circular at their base 26 or where they join the base and the upper edge 21. is in the form of an ellipse. "T '-.Figure 8 discloses that, the holding members are distorted substantially their full length and that the holding members are elliptical from about position indicated.at.28 to the free ends. In Figure 8 the fit between the stud and nut by way of example, may be class 3 standard in the body 20; and in the members 2| the fit may be tighter than class 4 but may be controlled. When the member 2|. is forced into the form 25, it assumes the position shown in Figure 9. When the forming tool is, removed the member 2| assumes, the position shown in Figure 10, looking down vertically-towards the locking portion of-.the fastener. V a

In views 1 and 2, the sides of the split cylinder are substantially parallel and substantially are vertical to the nut body faces. The sides are parallel also to the pitch line of the-threads therein. Thethreads are made inline with a standard tap or some othermeans .giving a standard thread. The forming tool, of suitable construction to give the desired torque, is pressed down vertically to the-nutbody faces, over the split cylinder. While the split cylinder is in the forming tool, the split portionsconform to the internal form of the tool, Itis important that the slots be positioned substantially on the long axis of the forming tool. What might be termed the edges of the slot-or slots are pulled away from the arc of the normal helix and/or pitch line so there is a definite and maximum binding on the short axis, the approximate mid-point between the slots.

I In the formed nut there is a minor but highly important thread deformation such that the threads at theouter face of the locking neck are closer on pitch than when threaded; this condition decreases as the topof the nut'body is approached. There is a progressive lead and helix warp present whichhas'the straightest lead and helix at'theouterface of the locking neckand the shortest as it approachesfthe nut body.

The displacement of the threads on the inner faces of the members 2!,as bestshown in Figures 6 .and 7 with respect to the threads 24 of the nut bore, sets up an axial" tension and gives theproven locking effect; 1 v

"The relative ofisetting'of the threads eifected 4 between adjacent edges or the holding members is an important feature of the invention, as it provides for a clamping tension of the holding members on the side faces of the mating threads of a bolt stem when the nut is applied.

In applications where great resistance to vibratory loosening is essential, or where a definite amount of torque in inch or foot pounds is required,for where constant or "frequent; disassembly is contemplated, applicants self binding nut gives completely satisfactory results.

With applicants device comparatively accurate torque of any practical degree may be obtained.

' There are several variables in this torque, viz: (a) the length of the torque neck; (b) the wall thickness of thetorque neck; (0) the width of the slot in the torque neck; (d) the amount of compression of the torque neck, etc. The torque neck is substantially compressed at the base to a tight thread,.an d this compression increases progressively to ,a substantially greater tightness at the top on the short axis. This procedure provides a gripping action ,on the bolt for substantially the entire length of the torque neck, and exerts tensionalpressure by the bolt on the threads of the nut body. Since this torque neck is a varying oval in shape after compression, and because the slot is coaxial to the long axis of the varying'oval (Figures 6, 7 and-l0), the slots are relieved from thread cutting. Because the varying oval, tor que neck is slotted, it has varying spring action," and thereipre retains, its torque strengththroughout repeated insertions of the bolt. The use of properly heat treated steel gives great life to this torque, I This torque is not noticeably affected by a reasonable amount of heat, cold, grease or water on thebolt. 1Also the bolt may be well started by hand, and the action of the torque neck is a gradual but increasingly grippingforce.

The relative olfsetting of the threads, between the leading edges of the holding members and the trailing edges provides for a clamping tension of the holding members on the side faces of the mating threads of a bolt stem for substantially the entire length of the holding members, when the nut is applied.-' I 'Whatweclaimisr l. The method of manufacturing a self-binding nut comprising formin'g a-n'ut blank with a reduced substantially cylindrical portion extending from an enlarged base portion, forming a circular bore through said'base portion and said reduced portion and concentric with said reduced portion, then threadingthe circular bore of the base and 'the'red'uced portion, forming a pair of diametrically opposed slots substantially the length of the reduced portion, deforming said reduced portion into substantially elliptical shape by forcing over the reduced portion agforming tool having an elliptical opening therein with the narrow axis of saidellipticalgopening less than' portion.

2. Themetho d of manufacturing a'self-bind ingnut comprising forming a nut blank with a reduced substantially 'cylindrical' portion extending from anenlarged base portion, forming acircular bore through said base portion and said reduced portion and concentric with said reduced portion, forming a pair of diametrically opposed slots substantially the length of the reduced portion, then threading the circular bore of the base and the reduced portion, deforming said reduced portion into substantially elliptical shape by forcing over the reduced portion a forming tool having an elliptical opening therein, with the narrow axis of said elliptical opening less than the outside diameter of the reduced portion, said forming tool being forced over the reduced portion for substantially its full length, with the short axis of the tool opening substantially perpendicular to a line between the slots and with the long axis of the opening in the forming tool substantially co-axial to the slots in reduced portion.

DANA C. ECKENBECK. PHILIP E. SLAUGHTER.

REFERENCES CITED The following references are of record in the file of this patent:

Number Re. 22,243 219,783 5 332,540 1,263,061 1,692,497 2,007,293 2,255,286 10 2,290,270

Number UNITED STATES PATENTS Name Date Gade Jan. 5, 1943 Vaughan Sept. 16, 1879 Law Dec. 15, 1885 Hibbard Apr. 16, 1918 Furlan Nov. 20, 1928 Cayouette July 9, 1935 Harvey Sept. 9, 1941 Brackett July 21, 1942 Brackett Nov. 2, 1943 Brackett Dec. 28, 1943 Mortus May 23, 1944 FOREIGN PATENTS Country Date Great Britain Apr. 3, 1930 Germany Feb. 19, 1881 France June 16, 1931

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